Heading down Highway 101 south of Cloverdale Monday morning, a pilot car leading a big rig drove off of the highway and crashed, seriously injuring the driver, according to the CHP.

The driver was taken by ambulance to Santa Rosa Memorial Hospital.

The 8:57 a.m. crash was between Asti and Geyserville. The Ford F-150 driver lost control and crashed to Zanzi Lane below the overpass.

Geyserville fire Capt. Joe Stewart said firefighters found a badly damaged pickup under the overpass. A passerby had believed the truck was on fire and used a fire extinguisher on the truck, Stewart said.

Geyserville, Cloverdale and Cal Fire firefighters responded. The injured man was treated by paramedics and rushed to the hospital by a Cloverdale ambulance.